Trigger-actuated control valve assemblies are conventionally utilized within fastener-driving tools so as to control the flow of air into and out from an upper air chamber which is disposed above the fastener-driving tool cylinder within which the fastener-driving piston, and the driver blade attached thereto, are movably disposed in order to drive and discharge fasteners through and out of the fastener-driving tool. During a typical fastener-driving tool firing cycle or operation, the upper air chamber is adapted to be charged with, and vented or exhausted of, air in accordance with the various stages of operation accompanying a fastener-driving cycle. An example of such a fastener-driving tool, within which such a trigger-actuated control valve assembly is disposed and utilized for controlling the flow of air into and out from the upper air chamber, is disclosed in U.S. Pat. No. 4,404,894 which issued to Oesterle on Sep. 20, 1983. In addition, as is also disclosed within FIG. 1, a conventional, PRIOR ART fastener-driving tool, generally indicated by the reference character 10, has a trigger-actuated control valve assembly 12 disposed therein, and the trigger-actuated control valve assembly 12 has an air passage 14 fluidically connected thereto, and incorporated within the fastener-driving tool housing 13, for controlling the air to be delivered to or charged into the upper air chamber, or for controlling the air to be vented or exhausted from the upper air chamber. More particularly, it is seen that the air passage 14 comprises a first, vertically oriented passageway or section 16 and, in order to achieve the fluidic communication between the first, vertically oriented passageway or section 16 and the trigger-actuated control valve assembly 12, it is necessary, to incorporate a second, angularly oriented or inclined passageway or section 18 within the fastener-driving tool housing 13. It is noted that a similarly structured air passage is disclosed within the aforenoted patent to Oesterle, however, in either case, it is extremely difficult to accurately machine such compound angle passages, particularly the angularly oriented or inclined passageways or sections thereof. Still further, such compound angle passages cannot be formed by means of a casting process in view of the fact that once the fastener-driving tool housing is fabricated from the cast material, which thereby forms the solid portions of the housing, around, in effect, mandrel members disposed within the mold structure for forming the aforenoted passages, there would be no way to extract or remove the mandrel members or structures from the cast housing structure.
Continuing further, it is additionally noted that, in connection with the fabrication of conventional, PRIOR ART trigger-actuated control valve assemblies, the trigger-actuated control valve assemblies usually comprise a multiplicity of component parts which therefore entails a substantially large inventory of component parts as well as a significant amount of time to assemble the component parts together. For example, the trigger-actuated control valve assembly comprises a housing which is usually fabricated as a two-part structure in order to be able to insert the actual trigger-actuated control valve mechanism internally therewithin, however, in accordance with a first type of trigger-actuated control valve assembly structure, separate fastener components, in the form of pins, rings, or the like, are required to fixedly secure the housing halves or complementary housing structures together. In accordance with a second type of trigger-actuated control valve assembly housing structure, the housing halves or complementary housing structures respectively comprise fastener components integrally formed thereon which have unique configurations, forms, contours, or the like that mandate or require the housing halves or complementary housing structures to be assembled together in a predetermined orientation or manner. Not only is the assembly or mating together of the housing halves or complementary housing structures therefore quite tedious, but in addition, the fabrication of such housing halves or complementary housing structures requires complex injection molding tooling.
A need therefore exists in the art for a new and improved trigger-actuated control valve assembly, for use within a fastener-driving tool, wherein the trigger-actuated control valve assembly can be fluidically connected to the upper control air chamber of the fastener-driving tool by means of externally disposed air passages which do not comprise compound angles and which can therefore be cast within the fastener-driving tool housing so as to effectively eliminate the need for machining such air passages in accordance with, or at, complex compound angle arrangements, wherein the trigger-actuated control valve assembly comprises two mating housing sections which can be readily assembled together in a relatively quick and easy manner without the need for separate fastener components to hold the assembled housing sections together, wherein the trigger-actuated control valve assembly comprises two mating housing sections which comprise interengaging fasteners which are integrally formed thereon and which are relatively easy to fabricate, and wherein the interengaging fasteners of the two mating housing sections of the trigger-actuated control valve assembly do not need to be necessarily oriented in a particular manner.